The present invention relates to an image display method and an image display apparatus in which surface and internal conditions of an examined object can be simultaneously displayed.
A method conventionally practiced in diagnostic medical applications comprises: acquiring data for the human internal tissue by image information acquisition means such as an X-ray CT (Computed Tomography) apparatus or a magnetic resonance image diagnostic apparatus; storing once the acquired data in image information storage means such as a magnetic tape, a magnetic disc, an optical disc or a semiconductor memory; randomly accessing the image information storage means to reconstruct an appropriate tomographic image; and displaying the image on display means such as a CRT.
The prior art includes a technique in which an X-ray CT apparatus or the like is employed to scan a plurality of slices to acquire a plurality of tomographic images which are used to produce an image closely resembling one viewed by endoscope observation. The technique has been disclosed by the present Applicant in Japanese Patent Application No. 8-187185 (1996).
In the above conventional technique, the surface condition of the internal wall etc. of the internal body tissue such as intestine tissue is represented when a three-dimensional (3D) image as viewed from a virtual endoscope is displayed. However, the combined representation thereof with information on the internal of tissue such as information on the internal of tissues composing the wall surface of the intestine, to continue with the above example, has not been possible.
That is, there is a problem that only the surface condition can be represented, but the internal condition which allows physicians to recognize, for example, how deep a tumor reaches inside the tissue, cannot be represented.
Moreover, although the above method allows an operator to arbitrarily change the field-of-view (FOV) centerline direction, it is difficult for the operator to spatially recognize the current FOV centerline direction, because reference images (axial, sagittal and coronal images) are not displayed synchronously with the change of the FOV centerline direction.